Methodology

This page explains where the data in our live tools comes from and what it can and cannot tell you. Our general rules are on the editorial standards page.

Earthquake tracker

• Sources: the Japan Meteorological Agency’s public earthquake list and the P2PQuake API (api.p2pquake.net).
• Refresh: both feeds are collected every 5 minutes.
• Duplicates: the same earthquake often arrives from both feeds. Reports close together in time and location are merged into one event, and the JMA record is preferred.
• Intensity: we show JMA seismic intensity (Shindo, 0 to 7) as the main measure, because it describes shaking at a place. Magnitude describes the energy released and is shown alongside it when reported.
• Limits: the tracker is not an official warning service and can lag the source feeds. For warnings, follow JMA and local authorities.

Festival and fireworks calendars

• Curated guides: each major festival has one canonical page with its kanji and romaji name, when it is held, and the sources it was checked against, with a verification date. A guide is only published as an indexable page with at least 350 words and sources on at least two different websites. Older listing URLs for the same festival redirect to the guide.
• Year-specific dates are refreshed from official and tourism sources each January. We do not convert vague timing (“early August”) into exact dates.
• Automated listings: other events are compiled automatically from event websites twice a day. Their details are not necessarily reviewed by a person and some descriptions are machine-generated, so these listings are kept out of search indexes. Confirm details with the organizer.

Cherry blossom forecasts

• JMA observes and announces when blossoms open (kaika) and reach full bloom (mankai) at its benchmark trees, but has not published bloom forecasts since 2010.
• Forecast dates on our sakura page come from private forecasters, chiefly the Japan Meteorological Corporation, and are labeled as forecasts. Forecasts change as the season approaches.

Autumn foliage forecasts

• JMA records maple and ginkgo color-change dates at its observation sites but does not forecast peak viewing.
• Forecasts on our koyo page are attributed to the private forecasters that issue them (the Japan Meteorological Corporation, Weathernews and the Japan Weather Association). Their methods and dates differ.

Time zone

All dates and times are Japan Standard Time (UTC+9) unless stated otherwise.

Questions or errors

If a figure looks wrong, please contact us with the page URL. Significant fixes are logged on the corrections page.